1. Field of the Invention
The present invention relates generally to guidance systems for farming vehicles, and more particularly, to a closed circuit video guidance system for a farming vehicle.
2. Decription of the Prior Art
Most farm crops are planted in rows to allow the use of mechanized farm equipment for plowing, planting, fertilizing, cultivating, defoliating and harvesting the crops. Rows of crops are typically spaced forty inches apart. The wheels of most farming vehicles are laterally spaced apart from each other in increments of forty inches corresponding to the distance between adjacent rows of crops. The farming vehicle can be driven through a field of crops without injuring the crops provided that the wheels of the farming vehicle travel within the furrows between adjacent rows. The farming vehicle typically includes one or more guide wheels which can be steered by the operator for maintaining the farming vehicle properly positioned with respect to the rows of farm crops.
Some farm crops, however, grow so tall and become so dense with foliage as to make it impossible for the operator to distinquish the positions of the rows and furrows. Under these circumstances, it often happens that the wheels of the farming vehicle leave the furrows and climb onto the rows of farm crops, thereby destroying the farm crops planted within the rows.
In the Southwestern portion of the United States, it is often necessary to irrigate farm crops. Irrigation is accomplished by flooding the furrow formed between two adjacent rows of farm crops. The furrows are flooded by supplying water to the furrows at one side of the field and allowing the water to spread through the furrow to the opposite side of the field. If the wheels of a farming vehicle are allowed to cross over from one row to the next, as when the operator has difficulty distinguishing the positions of the rows, then the furrows can become blocked midway through the field. In this event, irrigation water applied to the furrows at one side of the field is prevented from reaching farm crops located on the opposite side of the field. Thus, errors in steering the farming vehicle through the field of farm crops can result in a substantial loss in the yield of the farm crops.
One such crop which particularly presents the problems discussed above is cotton. Prior to harvest, the cotton plants grow from five to nine feet tall and produce a dense foliage. The leaves of the cotton plants produce a sticky sap which can stain the cotton during ginning and degrade the quality of the cotton unless the leaves are removed prior to harvesting the cotton. Thus, it is generally necessary to defoliate the cotton plants prior to harvesting the cotton. Defoliation is accomplished by spraying a chemical defoliant onto the leaves of the cotton plants. Typically, a spray tractor is driven through the field of cotton to apply the chemical defoliant to the leaves of the cotton plants. The rows and furrows formed within the field can be perceived by an observer positioned close to the ground. However, the tractor operator is positioned several feet above the uppermost portions of the cotton plants, and his view of the ground is completely blocked by the foliage of the cotton plants. Thus, the dense foliage of the cotton plants makes it extremely difficult for the operator of the spray tractor to constantly maintain the wheels of the tractor within the furrows.
It is therefore an object of the present invention to provide a guidance system for use in conjunction with a farming vehicle which allows an operator to steer the farming vehicle in accordance with identifying markings which can be perceived at ground level but which are difficult to perceive from the position at which the operator steers the farming vehicle.
It is a further object of the present invention to provide a guidance system for use in conjunction with farming vehicles which permits an operator to maintain the farming vehicle in proper alignment with the rows in which the farm crops are planted.
It is a still further object of the present invention to provide a guidance system for use in conjunction with a farming vehicle which allows an operator to drive the farming vehicle through a field of farm crops without injuring such crops.